UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General ...revision.peterhouse.co.zw/Biology/AS Level Biology... · UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate
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This document consists of 19 printed pages and 1 blank page.
1 Which steps are needed to find the actual width of a xylem vessel viewed in transverse section
using a ×40 objective lens?
1 Convert from mm to µm by multiplying by 10–3.
2 Calibrate the eyepiece graticule using a stage micrometer on ×10 objective lens.
3 Measure the width of the xylem vessel using an eyepiece graticule.
4 Multiply the number of eyepiece graticule units by the calibration of the eyepiece graticule.
A 1, 2, 3 and 4
B 2, 3 and 4 only
C 1 and 2 only
D 3 and 4 only 2 A specimen is viewed under a microscope using green light with a wavelength of 510 nm.
If the same specimen is viewed under the same conditions, but using red light with a wavelength of 650 nm instead, what effect will this have on the magnification and on the resolution of the microscope?
6 The diagram shows part of a carbohydrate molecule.
C O
CH2OH
CH2
HO
OHHO
HO
CH2OH
O
C O
HO
OHOHO O
C O
HO
OH
CH2OH
C O
HO
OH
If all the 1, 4 glycosidic bonds in this molecule are hydrolysed, how many water molecules will be used and how many separate glucose molecules will be produced?
number of water molecules used
number of glucose molecules produced
A 1 1
B 2 2
C 3 3
D 4 4
7 A peptide bond is formed between atoms of which two elements?
11 A fixed volume of the enzyme catalase was added to a fixed volume of hydrogen peroxide solution. The diagram shows how the rate of the reaction changed over the course of the reaction.
00
rate ofreaction
time
initial rateactual rate
Why did the actual rate of reaction decrease over time?
A The enzyme active sites become saturated.
B The enzymes were denatured.
C The product inhibited the reaction.
D The substrate molecules were used up. 12 Which levels of protein structure are always involved when competitive and non-competitive
13 The diagram shows the transport of ions across the cell surface membrane. Inside the cell there is a low concentration of sodium ions (Na+) and a high concentration of potassium ions (K+). Outside the cell there is a low concentration of K+ and a high concentration of Na+.
The carrier molecule is a pump which exchanges Na+ for K+ ions.
1
4
cell surfacemembrane
inside cell
outside cell
2
3carriermolecule
Which ionic movements are represented by the arrows?
active transport
of K+ active transport
of Na+ diffusion of Na+ diffusion of K+
A 2 3 1 4
B 2 3 4 1
C 3 2 1 4
D 3 2 4 1
14 Plant cells were immersed in solutions of different water potential and left for one hour.
Which row shows the effect of the different solutions on the plant cells?
water potential of solution compared to plant cells
21 A culture of bacteria had all its DNA labelled with the heavy isotope of nitrogen (15N). A sample
was taken and spun in a centrifuge.
The diagram shows the position of the DNA band at Z in the centrifuge tube.
X
Y
Z
The culture was then allowed to reproduce using nucleotides containing the normal isotope of nitrogen (14N). Samples were taken and spun in a centrifuge after one generation and again after two generations.
In which pattern would the DNA be found after the first and after the second generations?
after first generation after second generation
A half at X and half at Y quarter at X, quarter at Z and half at Y
B half at X and half at Z quarter at X, quarter at Z and half at Y
35 During an investigation on gas exchange, three measurements were made on four people. The efficiency of gas exchange was the same in all four people.
Which person, A, B, C or D, absorbed most oxygen during normal breathing?
breathing rate
/ breaths per minute tidal volume
/ dm3 total lung volume
/ dm3
A 14 0.6 6.4
B 15 0.6 6.0
C 16 0.5 6.4
D 17 0.5 5.8
36 The data shows how the number of human deaths caused by the bacterium
Staphylococcus aureus has changed from 1997 to 2005.
Methicillin is an antibiotic used to treat a disease caused by S. aureus. MRSA is methicillin-resistant S. aureus.
year total number of death
certificates with S. aureus total number of death certificates with MRSA
1997 369 355
1999 452 431
2001 456 681
2003 420 890
2005 428 1512
Which statement is not supported by this data?
A More people have MRSA so the disease spreads.
B MRSA is more likely to lead to death as there is no treatment.
C Resistant strains of MRSA are becoming more common.
D S. aureus will always cause humans to die. 37 An enzyme hydrolyses the two heavy polypeptide chains of an antibody molecule. The hydrolysis
occurs at the hinge region and breaks the antibody into three fragments.
How many of these fragments are able to bind to antigens?
40 The diagram shows the flow of energy between organisms in an ecosystem.
1 2
4
3
Which correctly identifies each organism in the ecosystem?
1 2 3 4
A primary
consumers
decomposers secondary
consumers
producers
B primary
consumers
secondary
consumers
producers decomposers
C secondary
consumers
decomposers producers primary
consumers
D secondary
consumers
primary
consumers
decomposers producers
20
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